code: def _denominator(equation):
      """find valid denominators for placeholder-simplified equations"""
      # placeholder-simplified: parenthesis-enclosed text is replaced by markers
      import re
  
      return [
          "".join(i).strip("/")
          for i in re.findall(
              r"(/\s*[\(\$\w\)]+)(\*\*[\(\$\w\)]+)?", equation
          )
      ]
  
imports: from numpy import ndarray, asarray, any
  from mystic._symbolic import solve
  from mystic.tools import list_or_tuple_or_ndarray, flatten
label_desc: Use image node_id 11 for calling a global function with example usage: _denominator(equation) and returns: unknown